You Didn't Know
by SecretofRavenclaw
Summary: Round 10 Quidditch League Fanfiction Competition: Sirius Black is currently in a relationship with James Potter's one and only but Sirius knows a secret that she doesn't.


**You Didn't Know?**

 **Author's note:** This is a story written for round 10 of the Quidditch League. This round was about forbidden relationships and mine was between family members. I went for far apart family members but this isn't going to be a very comfortable topic for some people, so just a warning. It is an AU fic where James Potter has a sister. Writing this was really difficult but you have to do stuff that you don't want to sometimes, so I guess I just had to like it or lump it.

 **Prompt:**

A forbidden relationship between family members (however distant)

 **Optional Prompts:**

2) (word) free

4) (word) careless

9) (word) practically

10) (dialogue) "What do you want from me?"

12) (word) anatomy

 **Disclaimer:** I don't' own Harry Potter but I do own my OC, Jennifer Potter.

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"You didn't know?" asked Sirius, his face showing a mixture of emotions. A simple shake of the head was the only answer he got before the woman in front of him broke down crying. "I'm sorry" he repeated, over and over, wishing that he had told the truth form the start.

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"What do you want from me?" asked James Potter, staring at the two people either side of him. The only answer he got was a matching set of glares and a sigh. Feeling the tension between the trio on the sofa he decided that maybe staying silent was best.

A voice from the other end of the Gryffindor, belonging to Remus Lupin, began yelling the name James at the top of his voice. "Ooops" James smiled, a slight bit of laughter to his voice, " I am leaving you for a second so I don't want any funny business going on between you to" he spoke, his eyes flitting between the pair. Neither replied but as the shouting got louder James realised he would have to leave them.

"So where were we?" asked Sirius Black, looking at the woman in front of him. Before being able to provide any sort of answer or other question, the woman opposite him began to move closer. Before long their lips were touching.

"You sure about this?" asked Sirius " I mean your brother is around some where." Instead of a spoken reply Sirius felt her lips meet his and began to kiss him. Relaxing into the kiss he looked into her sparkling hazel eyes to see the mixture of emotions within.

Seconds later the kiss was over after James grabbed Sirius and pulled him away. "That's my sister mate" he said, emphasising the word sister "You can't just go around kissing her, especially not in front of me." Sirius lowered his head, almost in shame, but deep inside he was smiling and laughing.

Protests could be heard from the girl approaching the pair or boys. " and as for you, Jennifer" James turned around to face her instead, "maybe I should warn our mother as to what you two are getting up to. I'm not sure that she would be that impressed but maybe I'm wrong." Sharing a look with Sirius, she also hung her head but knew given the next opportunity her and Sirius would kiss again.

"Now" James continued, " I'm going to go into my dorm and when I come back down I am going to find you to at least 5 metres apart form each other. Otherwise I am going to hex you into oblivion, and that is mostly a warning for Sirius." The only response was a small nod before he turned around and began his climb of the stairs.

Within seconds both were exiting the common room in favour of a place that they wouldn't be disturbed. The third door they tried opened to reveal an abandoned classroom. The door slammed shut as they both entered the room.

"You know that I saw you staring at me today" spoke Jennifer, her voice being carried in the dark, "We were in transfiguration and learning about the anatomy of some animal that we were mean to transfigure but out of the corner of my eye I could see you staring. For the entire hour your gaze didn't move from me. It's amazing really."

Before either really knew what was happening they had managed to find each other again in the dark classroom. As soon as Sirius made contact with her hand, he planted his lips on hers and began to kiss her. It ended as quickly as it had begun.

"I can't do it. It's just wrong" were the only phrases that Sirius was muttering whilst pacing. Jennifer followed his outline, her eyes never straying away from him, as she sat in the shadows. All she needed was an explanation as to his behaviour here but it seemed that there was something else that was bothering Sirius.

Bringing together all of her Gryffindor courage she opened her mouth to begin to question Sirius about what was going on but before she was able to get any words out, he began to speak.

"There is something I have to tell you" Sirius said in a hushed tone, guilt and fear the only emotions that could be seen. With a slight indication from Jennifer he continued talking, " I'm not sure that I can continue with… what ever this is." The questioning look from Jennifer was all he needed to provide an explanation. "We're related."

Expecting the worst, Sirius glanced at her as she began laughing. " If this is about my brother" she said, barely able to breathe through the laughter, "I'm going to kill him. I know that you view him as your legitimate brother, I mean you practically are, but that doesn't mean that I am actually your sister."

Finally regaining her composure she looked at Sirius, waiting for his answer. " No. I mean that we are actually related. We are some sort of cousins. I'm not sure exactly how but we most definitely are. I was so careless. When we began this I checked to try and find out but I came out with nothing. And now the truth is free. You didn't' know?" asked Sirius, his face showing a mixture of emotions. A simple shake of the head was the only answer he got before the woman in front of him broke down crying. "I'm sorry" he repeated, over and over, wishing that he had told the truth form the start.


End file.
